Refering to something by a certain name doesn't make it so. I can incorrectly call a bear a beaver, I can even publish a paper and refer to a bear as a beaver. It doesn't make the bear a beaver. People call Jeruselem Crickets, Potato Bugs. They are not. Never have been. Always been wrong, always will be.
A levee contains, controls, restricts, or directs flowing water in a river. Particularly rivers that tend to flood. i.e the Missouri, Mississipi. We have levees in California up on the Sacremento delta. None that I am aware of in So Cal.